The surface characteristics of a substrate can be altered by a variety of means, perhaps most readily by the application of a clear-coat layer. For example, the water permeability, dirt adherence resistance, wettability, and clarity properties of materials can be modified by suitable treatment of their surface. A number of compositions for altering the surface properties of substrates have been developed. Water repellant, oil repellent, stain resistant, anti-microbial, anti-static, anti-fog, anti-scratch and water absorptive surface treatments and coatings are well known commercial products.
Stain resistance, water repellency, and resistance to dirt adherence are important features in a clear-coat paint composition. Conventional coating compositions have chalking and whitening problems after exposure to the sun. Another issue with conventional coating compositions is coating compatibility and stability which negatively affect the clear coats ability to maintain its clarity over its lifetime. For example, clear-coat compositions composed of micron-size particles are prone to flocculation which can negatively alter the particle size distribution, and thus the assembly of the particles during the film drying process. This eventually results in coating film whitening and chalking. Although prior art methods and coating compositions work reasonably well, improvements are nonetheless desired.
Accordingly, there is a need for improved compositions of hydrophilic clear coating that have improved stain resistance, water repellency, and resistance to dirt adherence, while maintaining a clear character.